Lubricating oil additives and lubricating oil compositions



United States Patent LUBRICATING OIL ADDITIVES AND LUBRICAT- ING OILCQMPOSITIONS Carleton B. Scott, Pomona, and William L. Wasley, SantaAna, Calif., assignors to Union Oil Company of California, Los Angeles,Calif., a corporation of California No Drawing. Filed Oct. 7, 1957, Ser.No. 688,782 17 Claims. (Cl. 25232.7)

This invention relates to lubricating oil additives adapted to beingdiluted with mineral lubricating oils to produce lubricating oilcompositions. It ftu'ther relates to lubricating oils containing suchadditives. More particularly the invention relates to additive materialssuitable .for addition to lubricating oils to produce high viscosityindex lubricating oil compositions having good detergency andanticorrosion characteristics. It relates also to lubricating oilscontaining these additives with or without added anticorrosion,antirust, antioxidation agents, and the like. This is acontinuation-in-part of our copending application, Serial No. 602,074,filed August 3, 1956, now US. Patent No. 2,897,228.

Internal combustion engines, both of the spark ignition and compressionignition types, are constantly being improved With respect to increasedeliiciency and greater horsepower output, arnong other things. Withthese changes, improvements in lubricating oils suitable for use inthese engines are necessary. Among the requisite characteristics oflubricating oil compositions, suitable for use in the present dayengines of the types mentioned, are high viscosity index, detergency andanticorrosion properties. The viscosity index (V.I.) of an oil is ameasure of the extent to which the viscosity of the oil varies withtemperature, a high V.I. oil being one whose viscosity changes onlyslightly with change in temperature. The use of various polymericmaterials to improve the V.I. of lubricating oils is known.

The property of detergency, which is one of the requisitecharacteristics of lubricating oil, is one of preventing formation ofcarbonaceous and/or varnish-like deposits from accumulating on thevarious internal parts of the engine, e.g. on pistons, cylinder walls,in piston ring grooves, in hydraulic valve litters, and the like. Suchdeposits are particularly difficult to prevent and require the use of anexceptionally active detergent additive particularly in present dayautomotive engines where part or most of the driving is so-calledstop-and-go driving such as is encountered in city driving.

The property of anticorrosiveness is one of preventing the formationand/or accumulation within the oil of acidic bodies which attack themetal parts of the engine under conditions of use.

Although for many years lubricating oils designed for use in internalcombustion engines have contained various additive materials to impartthe characteristics referred to above, the extent of protection obtainedby such additives leaves something to be desired in the modern, highhorsepower output engines, particularly when these engines are operatedunder stopand-go driving conditions. Many attempts have been made toprepare a single additive material which is capable of imparting-all ofthe required characteristics to the base oil. However, for the mostpart, such additives have not proved entirely satisfactory. g

It is an object of this invention to provide a lubricating oil additivecapable of imparting high viscosity index and high detergency to amineral lubricating oil.

Another object of this invention is to provide an additive compositioncapable of imparting high V.I., high detergency and exceptionalanticorrosion characteristics to a mineral lubricating oil.

Another object of this invention is to provide a lubrimetaphosphate.

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2 eating oil containing an additive material capable of imparting thecharacteristics of high V.I., detergency antico-rrosiveness.

A further object of this invention is to provide a lubrieating oilhaving all of the characteristics described which consists of a minerallubricating oil containing a single additive material which is eifectivein imparting all of the described characteristics to said oil.

Other and related objects wlll be apparent from the followingdescription of the invention.

The additive material adapted for addition to mineral lubricating oil toimpart good detergency is prepared by reacting a monoolefin polymer or amonoolefin-diolefiu copolymer having an average molecular weight ofbetween about 5,000 and about 50,000, preferably between about 10,000and about 30,000, with an alkyl trithio- The resulting reaction productis then neutralized with a basic compound of an alkali metal orpreferably an alkaline earth metal. When anticorrosion characteristicsare particularly desired, the product may be super-based as will bedescribed hereinbelow. The additive material described very brieflyabove may be added to lubricating oil to produce an oil having thecharacteristics described herein.

Describing our invention more specifically the polymer or copolymer tobe used in the preparation of the additive will be a homopolymer of amonoolefin containing 3-6 carbon atoms or a polymer of a mixture ctmonoolefins containing from 36 carbon atoms in the molecule, or it maybe a copolymer of a monoolefin containing 3-6 carbon atoms with aconjugated diolefin containing from 4-7 carbon atoms in the molecule.The ratio of monoolefin to diolefin to be employed in preparing thecopolymer will preferably be between and 99.5 parts of the monoolefin tobetween 0.5, and 10 parts of the diolefin. Monoolefins which may be usedto prepare the polymers and copolymers include propylene, normalbutylene, isobutylene, 2methyl-butenel, Z-ethyl-butene l, and similarolefins containing 3-6 carbon atoms. Of these olefins the isoorbranched-chain monoolefins are preferred and isobutylene is particularlypreferred.

Polyolefins which may be used to copolymerize with the monoolefinsinclude isoprene, butadiene, 2-methyl -butadiene-l,3, 2-3-dirnethylbutadiene-l,3, hexadiene-2,4, cyclo-pentadiene, piperylene and the likehaving 4-7 car bon atoms. Of the polyolefins, isoprene and butadiene arepreferred. Of the various polymeric materials those prepared bycopolymerizing isobutylene and isoprene are particularly preferred.

The monoand diolefins may be employed in relatively pure form, in whichcase they are usually diluted with an inert liquid polymerizationmedium, or they may be employed in admixture with inert components. Forexample, in preparing polyisobutylene for use in accordance with theinvention, the isobutylene may be provided in relatively pure form or itmay be employed in the form of a mixture of isobutylene and butane, suchas is produced as a by-product from petroleum refining processes.Similarly in preparing copolymers the diolefin as well as the monoolefinmay be employed in admixture with inert constituents.

The polymerization reaction is eifected at low temperatures, e.g., atfrom about --20 C. to about C., preferably from about 50 C. to about 80C., under the influence of a Friedel-Crafts type catalyst such asaluminum chloride, aluminum bromide, zinc chloride,

boron trifluoride, titanium tetrachloride, etc., and preferably .in thepresence of an inert liquid hydrocarbon or halogenated hydrocarbonreaction medium. In general, conventional techniques such as thosedescribed in US. Patent No. 2,356,128 are employed, and the variousprocess variables are controlled in the known manner to produce apolymeric product whose molecular weight is between about 5,000 andabout 50,000, preferably be tween about 10,000 and about 30,000.Conveniently, the reaction is carried out continuously in a tubularreactor which may take the form of a copper coil provided with exteriorcooling means capable of maintaining the desired low polymerizationtemperature. The monoolefin, or mixture of monoolefin and diolefin, andthe liquid reaction medium, either as separate entities or as apreviously-formed mixture, are continuously introduced into therefrigerated coil. At a point within the coil where the olefinicreactant and the reaction medium have been thoroughly mixed and/orcooled, for example, to about 75 C., there is introduced a stream ofcatalyst, e.g., a mixture of boron trifluoride in methane, ethane,propane, or other inert diluent, containing 5 to 50 parts of diluent perpart of boron trifiuoride. The polymerization reaction is exothermic,and the reaction temperature and reaction rate (and hence also themolecular weight of the product) can readily be controlled by suitablyvarying the rate of catalyst addition and/ or the catalystconcentration. Generally, between about 0.1 and about 3 parts by weightof catalyst are provided per 100 parts by weight of polymerizableolefin. The polymerization may be carried to completion, i.e., to pointof maximum molecular weight of the product under the particularconditions employed, or it may be stopped at any desired intermediatepoint by quenching the reaction by the addition of an alcohol, ether orketone. As stated, the polymerization reaction should be so controlled,either by suitably selecting the reaction temperature, the amount ofinert liquid reaction medium present, the identity, concentration andrate of addition of the catalyst, by use of a quenching agent, or by acombination of these means, to stop the reaction at the desired point soas to obtain a polymeric product having an average molecular weightbetween about 5,000 and about 50,000. Processwise, there is nodistinction between the homopolymers and copolymers, i.e., the sametechniques, reaction conditions, catalysts, reaction media, etc. areemployed regardless of whether the product being prepared is ahomopolymer of a monoolefin or a copolymer thereof with a diolefin. Themost desirable copolymers contain from about 0.005 to about 0.1,preferably from about 0.01 to about 0.05, part of the diolefin per partof the monoolefin.

Upon completion of the polymerization reaction, the polymeric product isobtained in the form of a viscous solution of the same in the liquidreaction medium. the polymer is to be stored for any appreciable periodof time before being reacted with an alkyl trithiometaphosphate, it ispreferably washed several times with water to remove any catalyst and aportion of the solvent is distilled off to strip off traces of water andunpolymerized olefinic material.

The alkyl trithiometaphosphates, which are employed to react with thepolymers and copolymers described, are the methyl trithiometaphosphateand ethyl trithiometaphosphate. These compounds are made by reactingphosphorus pentasulfide with methyl or ethyl mercaptan or with trimethylor triethyl tetrathioorthophosphate. In preparing the compounds withmethyl or ethyl mercaptan, a mixture of the phosphorus pentasulfide andat least about 4 molecular equivalents of the desired mercaptan arereacted at temperatures of 90200 C. for 2 to 40 hours under sufiicientpressure to maintain the reactants in the liquid phase. Reaction may becarried out in an inert reaction medium such as benzene, toluene, or thelike. In preparing these same compounds by reacting phosphoruspentasulfide with trimethyl or triethyl tetrathioorthophosphate, thereaction is effected at temperatures between about 90 C. and 200 C. for2 to 20 hours. In this instance also it is preferable to carry out thereaction in the presence of an inert reaction medium such as benzene,toluene or xylene.

In reacting the hydrocarbon polymers and copolymers describedhereinabove with methyl or ethyl trithiometaphosphates 1 part of thepolymeric material in solution in a diluent, e.g. naphtha, toluene,xylene or the like or preferably a light mineral lubricating oil such as90 neutral oil (a light neutral lubricating oil having a viscosity ofabout 38 seconds Saybolt Universal at 210 F. and a viscosity index ofabout 84) is heated with 0.01 to 0.15 part of methyl or ethyltrithiometaphosphate at temperatures of 20 C. to 190 C. for 2 to 10hours depending on the reactivity of the polymer or copolymer. Theproduct may be neutralized and/or super based directly or may first befiltered using any well known filter aid such as a clay. In the eventone of the hydrocarbon diluents mentioned is used the diluent may beremoved by evaporation to obtain the reaction product or 90 neutral oilor like oil may be added prior to evaporation of the diluent.

The acidic reaction product may be reacted with a chemically equivalentamount of alkali metal base or preferably an alkaline earth metal baseat elevated temperatures to effect neutralization and the resultingproduct filtered hot through a filter aid to obtain the additive in theform of oil concentrate. This concentrate will preferably contain 15% to50% by weight of the neutralized reaction product in light minerallubricating oil.

Preferably the acidic reaction product either before or afterneutralization will be reacted with an amount of base sufiicient toproduce a super based material. The amount of excess base will bebetween 1.1 and 3.5 equivalents per equivalent of acidic reactionproduct or between 0.1 and 2.5 equivalents per equivalent of neutralizedreaction product.

The super basing is eflected in the presence of 0.05 to 0.4 part byweight of an alkyl substituted phenol having between about 4 and 5 andabout 12 side-chain carbon atoms. Phenols suitable for this purposeinclude tertbutylphenol, isobutylcresol, n-octylphenol, mixed nonylphenols, mixed dodecylphenols, dihexylphenol, etc. The mixture of acidicor neutralized phosphorusand sulfurcontaining reaction product, andphenol is heated to between 100 C. and 180 C. and the metal base isadded over a period of 1 to 4 hours. A small amount of water ispreferably added along with the base. After reaction is complete themixture is heated for an additional 1 to 4 hours at about 110 C. to 180C. to insure completion of the reaction and dehydration of the reactionproduct. Any basic compound of any of the alkaline earth metals, e.g.,the oxides, hydroxides, carbonates, etc., of calcium, barium, orstrontium, may be employed, but the oxide and hydroxide of barium arepreferred. If desired, a combination of such bases may be employed,e.g., one metal base may be employed to neutralize the acidic 1 reactionproduct and another metal base may be employed to provide the desiredalkaline reserve. Also, if desired, an alkali metal base such as sodiumor potassium hydroxide or carbonate may be employed to neutralize theacidic reaction product and an alkaline earth metal base employed toprovide the alkaline reserve.

Following the above treatment sufficient light mineral lubricating oilis added to give an additive concentrate containing 15% to 50% by weightof additive in oil.

In preparing the finished mineral lubricating oil of this invention theadditive concentrate or additive in any form, such as pure additiveproduct, is dissolved in or mixed with mineral lubricating oil to givean oil containing from about 1 to about 10% by weight of additive. Sincethe additive is oil-soluble it is merely necessary to add the additiveor additive concentrate to the oil with mixing to obtain the finishedlubricating oil. This may be accomplished at ordinary or elevatedtemperatures. The lubricating oil is preferably a solvent treated anddewaxed mineral lubricating oil fraction. By solvent treated is meantextracted with a selective solvent which selectively dissolves andremoves the more aromatic portion of the petroleum fraction. Solventsand methods of solvent treating are well known in the art and need notbe further described. Oils having viscosity indexes above about 80 arepreferred but not essential since the additives described herein willimpart improved V.I., detergency and anticorrosion characteristics tosubstantially any mineral lubricating oil.

Lubricating oils of this invention have been tested in a standard 1954Chevrolet Power-Glide engine. In this test the engine is run for a totalof 54 hours under varying conditions of load and temperature. The engineis operated for 2 hours under the conditions set forth in column A,below, then for 2 hours under the conditions set forth in column B, andfinally for 2 hours under the conditions set forth in column C. Thiscycle is repeated 16 times, and the engine is disassembled and inspectedfor general condition and cleanliness.

TEST CONDITIONS Speed, rpm... Load, lbs Brake H. P Water Temp;

F. in.

F. out Oil Temp, F

The apparatus consists of 18 'feet of 0.25-inch copper tubing in theform of a coil mounted in a Dry Ice and acetone bath. The inlet end ofthe coil is equipped with two fittings through which monomeric olefinand solvent can be introduced into the coil. A second'fitting for theintroduction of catalyst is positioned about 14 feet from the inlet endof the coil, and the outlet end of the coil feeds into a receiver.Suitable throttling valves, flow meters and associated equipment areprovided for controlling the rate at which the olefin, solvent andcatalyst are introduced into the coil, and thermocouples are providedfor determining the temperature of the reaction mixture within the coil.

In a typical polymer preparation, isobutylene and pentane are introducedinto the coil at rates of about 400 parts and about 1300 parts per hour,respectively. The catalyst, consisting of a mixture of 1 part of borontrifiuoride and 20 parts of propane, is introduced at a rate of about1.5 parts per hour. At these flow rates, the temperature of the reactionmixture is about -65 C. to 75 C., and the reaction time is about 1.5minutes. The product collected in the receiver is a pentane solution (ofabout 23% concentration) of an isobutylene polymer having an averagemolecular weight of about 25,000. This solution is concentrated'to about35% by distilling off the required amount of'solvent.

Approximately 4,000 parts of the 35 polyisobutylene solution is thendiluted with 1400 parts of 90 neutral oil, and is heated to about 150 C.and blown with nitrogen to remove the pentane solvent. To this solutionof polymer is slowly added 140 par-ts of methyl trithiometaphosphatewhile heating the mixture at 150 C. for about 2 hours. Following theaddition of metaphosphate the mixture is heated for an additional 4hours at about the same temperature and then filtered hot.

One hundred parts of the product so obtained is mixed with 10 parts ofn-hexylphenol and heated with stirring to 135 C., after which there isadded 17.5 parts of barium hydroxide pentahydrate over a period of 1hour. Heating is continued for about 4 hours, during which about 13parts of water are added. The product is dehydrated by heating to 165 C.after which it is diluted with about 100 parts of neutral oil andfiltered through diatornaceous earth to obtain a finished additiveconcentrate.

A lubricating oil is prepared by dissolving 10 parts of the additiveconcentrate in parts of a mineral oil consisting of equal parts of 90neutral oil and 300 neutral Oil. The 300 neutral oil is an oil similarto 90 neutral oil described hereinabove except that it has a SayboltUniversal Viscosity at 100 F. of about 326 seconds and at 210 F. ofabout 52.5 seconds and a VI. of 86. The above oil, having a VI. of about135, in the Chevrolet engine test shows a detergency rating of 90. Thebase oil, i.e. the mixture of 90 neutral and 300 neutral oil has adetergency rating of 60.

Example 11 Example I is repeated using ethyl trithiometaphosphate inplace of methyl trithiornetaphosphate. The results are substantiallyidentical to those of Example I.

Example III The polymerization procedure of Example I is followed exceptthat suificient isoprene is dissolved in the pentane solvent so that thepolymeric product obtained is a 35 pentane solution of a 97-to-3copolymer of isobutylene and isoprene. Approximately 4,000 parts of thiscopolymer solution are admixed with 1400 parts of 90 neutral oil, andthe resulting mixture is heated at about C. while blowing with nitrogento remove the pentane sol vent. The resulting product is then admixedwith 140 parts of methyl trithiometaphosphate and the temperature isincreased to about C. and held there for about 6 hours. The acidicproduct is then filtered and cooled.

A 100-part portion of the product so obtained is mixed with 4 parts ofoctylphenol and heated to 130 C. while 17.5 parts of barium hydroxidepentahydrate are added over a period of 1 hour. Heating is continued forabout 4.5 hours during which. time 12.5 parts of water are added toreplace that lost by evaporation. The product is diluted with 100 partsof 90 neutral oil and filtered to obtain an additive concentrate. Alubricating oil is prepared by dissolving 10 parts of the additiveconcentrate in 100 parts of a mixture of equal parts of 90 neutral and300 neutral oil. This lubricating oil has a V.'I. of 138 and adetergency rating of 91 in the Chevrolet engine test.

Example IV Example III is repeated using calcium hydroxide in place ofbarium hydroxide to neutralize and super base the acid reaction productof copolymer and methyl trithiometaphosphate. I

A lubricating oil prepared in the manner described in Example 111 has adetergency rating of 90.

Example V Example VI Example III is repeated except that the acidicproduct I is simply neutralized with barium hydroxide pentahydrate inthe absence of alkyl phenol. The additive concentra-te is used toprepare alu-bricating oil using an SAE.

10 solvent-treated and dewaxed Western parafiinic min- 7 erallubricating oil and sufiicient of the concentrate to impart an additiveconcentration of 3% by weight. This lubricating oil has a detergencyrating of 87.

Other modes of applying the principle of our invention may be employedinstead of those explained, change being made as regards the methods ormaterials em ployed, provided the compositions stated by any of thefollowing claims, or the equivalent of such stated compositions, beobtained.

We claim:

1. A lubricating oil additive composition adapted for addition tomineral lubricating oil to produce a lubricating oil composition havinghigh viscosity index, detergent and anticorrosion characteristics, saidadditive composition consisting essentially of a mineral lubricating oilcontaining between about 15% and about 50% by weight of a productobtained by reacting 1.0 part of a hydrocarbon polymer selected from theclass consisting of the homopolymers of monoolefins containing from 3 to6 carbon atoms, and copolymers of said monoolefins with between about0.005 and about 0.1 part by weight of a conjugated diolefin containingfrom 4 to 7 carbon atoms, said polymer having an average molecularweight between 5,000 and 50,000, said hydrocarbon polymer being preparedat a temperature between 20 C. and -100 C. using a Friedel-Craftscatalyst, with between about 0.01 and about 0.15 part of a compoundselected from the class consisting of methyl trithiometaphosphate andethyl trithiometaphosphate, at a temperature between about 20 C. andabout 190 C. for between about 2 and about hours to produce an acidicphosphorus and sulfur-containing reaction product and neutralizing thelast named reaction product with a metal base of the class consisting ofthe alkali and alkaline earth metal bases.

2. A lubricating oil composition consisting essentially of a minerallubricating oil having dissolved therein sufiicient of the additivecomposition defined by claim 1 to impart to said lubricating oil betweenabout 1% and about 10% of additive by weight, said amount beingsufiicient to enhance substantially the viscosity index, detergent andanticorrosion characteristics of said oil.

3. A lubricating oil additive composition adapted for addition tomineral lubricating oil to produce a lubricating oil composition havinghigh viscosity index, detergent and anticorrosion characteristics, saidadditive composition consisting essentially of a mineral lubricating oilcontaining between about and about 50% by weight of a product obtainedby reacting 1.0 part of a hydrocarbon polymer selected from the classconsisting of the homopolymers of monoolefins containing from 3 to6carbon atoms, and copolymers of said monoolefins with between about0.005 and about 0.1 part by weight of a conjugated diolefin containingfrom 4 to 7 carbon atoms, said polymer having an average molecularweight between 5,000 and 50,000, said hydrocarbon polymer being preparedat a temperature between C. and -100 C. using a Friedel-Crafts catalyst,with between about 0.01 and about 0.15 part of a compound selectedfromthe class consisting of methyl trithiometraphosphate and ethyltrithiometaphosphate, at a temperature between about 20 C. and about 190C. for between about 2 and about 10 hours to produce an acidicphosphorus and sulfur-containing reaction product, and reacting theproduct so obtained with between about 1.1 and about 3.5 equivalents ofan alkaline earth metal base per equivalent of said acid reactionproduct, together with between about 0.05 to about 0.4 part by weightper part by weight of acidic reaction product of an alkyl substitutedphenol having from 4 to 12 side chain carbon atoms. V

4. A lubricating oil additive composition according to claim 3 in whichsaid compound is methyl trithiometaphosphate.

5. A lubricating oil additive composition according to 8 claim 3 inwhich said compound is ethyl trithiometaphosphate.

6. A lubricating oil additive composition according to claim 3 in whichsaid alkaline earth metal base is barium hydroxide.

7. A lubricating oil additive composition according to claim 3 in whichsaid polymer is a polyisobutylene having an average molecular weightbetween about 10,000 and about 30,000.

8. A lubricating oil additive composition according to claim 3 in whichsaid polymer is a copolymer of isobutylene and isoprene having anaverage molecular weight between about 10,000 and about 30,000.

9. A lubricating oil composition consisting essentially of a minerallubricating oil having dissolved therein sufiicient of the additivecomposition defined by claim 3 to impart to said lubricating oil betweenabout 1% and about 10% of additive by weight, said amount beingsufficient to enhance substantially the viscosity index, detergent andanticorrosion characteristics of said oil.

10. A lubricating oil composition consisting essentially of a minerallubricating oil having dissolved therein sufiicient of the additivecomposition defined by claim 4 to impart to said lubricating oil betweenabout 1% and about 10% of additive by weight, said amount beingsufficient to enhance substantially the viscosity index, detergent andanticorrosion characteristics of said oil.

11. A lubricating oil composition consisting essentially of a minerallubricating oil having dissolved therein sufficient of the additivecomposition defined by claim 5 to impart to said lubricating oil betweenabout 1% and about 10% of additive by weight, said amount beingsuflicient to enhance substantially the viscosity index, detergent andanticorrosion characteristics of said oil.

12. A lubricating oil composition consisting essentially of a minerallubricating oil having dissolved therein sufiicient of the additivecomposition defined by claim 6 to impart to said lubricating oil betweenabout 1% and about 10% of additive by weight, said amount beingsuflicient to enhance substantially the viscosity index, detergent andanticorrosion characteristics of said oil.

13. A lubricating oil composition consisting essentially of a minerallubricating oil having dissolved therein sutlicient of the additivecomposition defined by claim 7 to impart to said lubricating oil betweenabout 1% and about 10% of additive by weight, said amount beingsutficient to enhance substantially the viscosity index, detergent andanticorrosion characteristics of said oil.

14. A lubricating oil composition consisting essentially of a minerallubricating oil having dissolved therein suificient of the additivecomposition defined by claim 8 to impart to said lubricating oil betweenabout 1% and about 10% of additive by Weight, said amount beingsufficient to enhance substantially the viscosity index, de terent andanticorrosion characteristics of said oil.

15. A lubricating oil additive composition adapted for addition tomineral lubricating oil to produce a lubricating oil composition havinghigh viscosity index, detergent and anticorrosion characteristics, saidadditive composition consisting essentially of a mineral lubricating oilcontaining between about 15% and about 50% by weight of a productobtained by reacting 1.0 part of a hydrocarbon polymer selected from theclass consisting of the homopolymers of monoolefins containing from 3 to6 carbon atoms, and copolymers of said monoolefins with between about0.005 and about 0.1 part by weight of a conjugated diolefin containingfrom 4 to 7 carbon atoms, said polymer having an average molecularweight between 5,000 and 50,000, said hydrocarbon polymer being preparedat a temperature between 20 C. and C. using a Friedel-Crafts catalyst,with between about 0.01 and about 0.15. part of a compound selected fromthe class consisting of methyl trithiometaphosphate and ethyltrithiometaphosphate, at a temperature between about 20". C. and aboutC. for between about 2 and 9 about 10 hours to produce an acidicphosphorus and sulfur-containing reaction product, neutralizing the lastnamed reaction product with a metal base of the class consisting of thealkali and alkaline earth metal bases and heating the neutralizedproduct with 0.05 to 0.4 part of an alkyl substituted phenol containing4 to 12 side chain carbon atoms to a temperature of 100 C. to 180 C.,and adding thereto 0.1 to 2.5 equivalents of an alkaline earth metalbase per equivalent of neutralized product.

16. A lubricating oil composition consisting essentially of a minerallubricating oil having dissolved therein sufficient of the additivecomposition defined by claim 15 to impart to said lubricating oilbetween about 1% and about 10% of additive by weight, said amount beingsuflicient to enhance substantially the viscosity index, detergent and'anticorrosion characteristics of said oil.

17. A lubricating oil additive composition adapted for addition tomineral lubricating oil to produce a lubricating oil composition havinghigh viscosity index and detergent characteristics, said additivecomposition consisting essentially of a mineral lubricating oilcontaining between about 15% and about 50% by weight of a productprepared by reacting a metal base of the class consisting of the alkaliand alkaline earth metal bases with an acidic phosphorusandsulfur-containing reaction product of 10 between about 0.01 and about0.15 part of a compound selected from the class consisting of methyltrithi0metaphosphate and ethyl trithiometaphosphate and 1.0 part of ahydrocarbon polymer selected from the class consisting of thehomopolymers of monooleiins containing from 3 to 6 carbon atoms andcopolymers of said monoolefins and between about 0.005 and about 0.1part by weight of a conjugated diolefin containing from 4 to 7 carbonatoms, said polymer having an average molecular weight, between about5,000 and about 50,000, said hydrocarbon polymer being prepared at atemperature between '20 C. and C. using a Friedel-Crafts catalyst, theamount of said metal base being that amount necessary to neutralize saidacidic reaction product.

References Cited in the file of this patent UNITED STATES PATENTS2,316,080 Loane et al. Apr. 6, 1943 2,316,082 Loane et al. Apr. 6, 19432,561,773 Augustine July 24, 1951 2,767,164 Asseif et al. Oct. 16, 19562,768,954 Fields Oct. 30, 1956 2,768,999 Hill Oct. 30, 1956 2,838,484Karll et al. June 10, 1958

1. A LUBRICATING OIL ADDITIVE COMPOSITION ADAPTED FOR ADDITION TOMINERAL LUBRICATING OIL TO PRODUCE A LUBRICATING OIL COMPOSITION HAVINGHIGH VISCOSITY INDEX, DETERGENT AND ANTICORROSION CHARACTERISTICS, ANDADDITIVE COMPOSITION CONSISTING ESSENTIALLY OF A MINERAL LUBRICATING OILCONTAINING BETWEEN ABOUT 15% AND ABOUT 50% BY WEIGHT OF A PRODUCTOBTAINED BY REACTING 1.0 PART OF A HYDROCARBON POLYMER SELECTED FROM THECLASS CONSISTING OF THE HOMOPOLYMERS OF MONOOLEFINS CONTAINING FROM 3 TO6 CARBON ATOMS, AND COPOLYMERS OF SAID MONOOLEFINS WITH BETWEEN ABOUT0.005 AND ABOUT 0.1 PART BY WEIGHT OF A CONJUGATED DIOLEFIN CONTAININGFROM 4 TO 7 CARBON ATOMS, SAID POLYMER HAVING AN AVERAGE MOLECULARWEIGHT BETWEEN 5,000 AND 50,000 SAID HYDROCARBON POLYMER BEING PREPAREDAT A TEMPERATURE BETWEEN -20*C. AND -100* C. USING A FRIEDEL-CRAFTSCATALYST, WITH BETWEEN ABOUT 0.0U AND ABOUT 0.15 PART OF A COMPOUNDSELECTED FROM THE CLASS CONSISTING OF METHYL TRITHIOMETAPHOSPHATE ANDETHYL TRITHIOMETAPHOSPHATE, AT A TEMPERATURE BETWEEN ABOUT 20*C. ANDABOUT 190*C. FOR BETWEEN ABOUT 2 AND ABOUT 10 HOURS TO PRODUCE AN ACIDPHOSPHORUS AND SULFUR-CONTAINING REACTION PRODUCT AND NEUTRALIZING THELAST NAME REACTION PRODUCT WITH A METAL BASE OF THE CLASS CONSISTING OFTHE ALKALI AND ALKALINE EARTH METAL BASES.